5.3 Files

You might also need to check for the existence of files. Before using
these macros, ask yourself whether a runtime test might not be a better
solution. Be aware that, like most Autoconf macros, they test a feature
of the host machine, and therefore, they die when cross-compiling.

Check whether file file exists on the native system. If it is
found, execute action-if-found, otherwise do
action-if-not-found, if given. The result of this test is cached
in the ac_cv_file_file variable, with characters not
suitable for a variable name mapped to underscores.

Executes AC_CHECK_FILE once for each file listed in files.
Additionally, defines ‘HAVE_file’ (see Standard Symbols)
for each file found. The results of each test are cached in the
ac_cv_file_file variable, with characters not suitable for
a variable name mapped to underscores.